Filling materials and methods of filling through holes for improved adhesion and hermeticity in glass substrates and other electronic components

ABSTRACT

A method of processing a glass substrate for use in semi-conductor packaging applications. Through holes are created in a glass substrate and subsequently filled with a metallized paste material. The glass substrate is planarized after metallization to clean and flatten a surface of the glass substrate. The surface of the glass substrate is coated with at least one redistribution layer of a metal, a metal oxide, an alloy, a polymer, or a combination thereof. The paste material has improved adhesion to the through-holes. The filled through-holes are hermetic and have a low resistivity.

CROSS REFERENCE

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/947,577, filed Mar. 4, 2014, and U.S. Provisional PatentApplication No. 61/985,697, filed Apr. 29, 2014, the specification(s) ofwhich is/are incorporated herein in their entirety by reference.

This application claims priority to U.S. patent application Ser. No.13/666,089, filed Nov. 1, 2012, which is a non-provisional of U.S.Provisional Patent Application No. 61/554,417, filed Nov. 1, 2011, thespecification(s) of which is/are incorporated herein in their entiretyby reference.

FIELD OF THE INVENTION

The present invention relates to a method of creating through-holes inglass substrates and filling the through-holes with materials to connectintegrated circuits for use in electronic applications.

BACKGROUND OF THE INVENTION

Semiconductor devices are constantly responding to the market demand forfaster, smaller, higher data and less expensive devices. Devices areexpected to deliver more functionality at greater speeds in smallerdimensions and with capabilities of electrical and optical signals. Thisrequires a new packaging scheme that can integrate heterogeneous devicessuch as logic, memory, power, graphics, sensors and other integratedcircuits and components in a single package where improved electricalperformance is also achieved by having these devices in close proximity.

Microscopic through-holes in a glass substrate are filled with materialsthat are usually metallized, and can act as connectors between the topand bottom surface of the glass substrate to transfer electronic signalsand currents to semiconductor or other devices. Glass and glassysubstrates include borosilicate, quartz, sapphire, and other substrateswith, toughness, pressure sensitivity, thermal expansion, dielectricproperties and transparency designed for specific applications.

The present invention provides a simple and low cost method thatachieves excellent adhesion and hermeticity between the filling materialand glass substrate.

Any feature or combination of features described herein are includedwithin the scope of the present invention provided that the featuresincluded in any such combination are not mutually inconsistent as willbe apparent from the context, this specification, and the knowledge ofone of ordinary skill in the art. Additional advantages and aspects ofthe present invention are apparent in the following detailed descriptionand claims.

SUMMARY OF THE INVENTION

The present invention features a method of processing a glass substratefor use in semi-conductor applications. In some embodiments, the methodcomprises filling through-holes of the glass substrate with a metallizedpaste material using thick film technology, planarizing the glasssubstrate after metallization to clean and flatten a surface of theglass substrate, coating the surface of the glass substrate with atleast one redistribution layer of a metal, a metal oxide, an alloy, apolymer, or a combination thereof.

The present invention also features a method of creating through-holesin a glass substrate. In some embodiments, the method comprisesstrengthening the glass substrate to increase durability during the holecreation and subsequent processes, treating a surface of the glasssubstrate with a protective layer, creating the hole in the glasssubstrate, and heat treating the glass substrate to repair damage fromthe hole creation process.

In some embodiments, the method comprises barrel-coating the hole withat least one layer, curing the coated hole, metallization of the holeand heat treating the glass substrate. In some embodiments, the methodfurther comprises strengthening the glass substrate prior tobarrel-coating to increase durability. In some embodiments, the methodfurther comprises cleaning the glass substrate prior to filling.

In some embodiments, a paste material is used for filling a through-holefor improved adhesion and hermeticity in glass substrates. In someembodiments, the paste material comprises a metal, a glass fritcomposition, a solvent, a resin, and inert additives.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of a glass substrate and filledthrough-hole of the present invention.

FIG. 2 shows a cross-sectional view of an alternative embodiment of thepresent invention.

FIGS. 3A-3E show cross-sectional views of alternative embodiments of thepresent invention.

FIG. 4 shows a cross-sectional view of a glass substrate and filledthrough-hole of the present invention.

FIG. 5 shows a cross-sectional view of a glass substrate and filledthrough-hole of the present invention.

FIG. 6 shows a cross-sectional view of a filled through-hole of thepresent invention.

FIG. 7 shows a schematic of the cross-sectional view of a metallizedthrough-hole of the present invention.

FIG. 8 shows a schematic of the cross-sectional view of redistributionlayers disposed on a surface of the glass substrate and a metallizedthrough-hole of the present invention.

FIG. 9 shows a schematic of the cross-sectional view of redistributionlayers disposed on a surface of the glass substrate and a metallizedthrough-hole of the present invention.

FIG. 10 shows a schematic of alternative embodiments of a filled-throughhole of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Creating Through-Holes

As used herein, the word “hole” and “through-hole” are usedinterchangeably. As used herein, the term “substantially” is defined asbeing largely that which is specified. As used herein, the term“partially” is defined as being to some extent, but no wholly, thatwhich is specified. As used herein, the term “completely” is defined asbeing wholly or entirely that which is specified.

Referring now to FIGS. 1-10, the present invention features a method ofcreating through-holes in a glass substrate. In some embodiments, themethod comprises strengthening the glass substrate to increasedurability during the hole creation and subsequent processes, treating asurface of the glass substrate with a protective layer, creating thehole in the glass substrate, and heat treating the glass substrate torepair damage from the hole creation process.

In some embodiments, the glass substrate is strengthened by heating theglass substrate. In some embodiments, the heat treated by annealing theglass substrate.

In some embodiments, the protective layer catches debris and protectsthe surface during creation of the hole. In some embodiments, theprotective layer is printed, laminated, sprayed or spin coated onto theglass substrate. In some embodiments, the protective layer comprises anorganic material, such as Emulsitone or an equivalent material. In someembodiments, the protective layer is a polymer coating or a paste.

In some embodiments, the hole is created by etching the glass substrate.In some embodiments, the hole is dry etched into the glass substrate. Insome embodiments, the hole is wet etched into the glass substrate. Insome embodiments, the protective layer is a photopolymer, a photoresist,or a silicon based material or compound such as Silicon Nitride, whichhave all been imaged. In some embodiments, a portion of the protectivelayer is exposed to ultraviolet light to harden the photopolymer andprevent the hardened photopolymer from being etched or reversed based onpositive or negative photoresist type. In some embodiments, theprotective layer is developed to create holes on the surface of theglass substrate. In some embodiments, the hole is etched at leastpartially through the glass substrate thickness. In some embodiments,the hole is etched at completely through the glass substrate thickness.In some embodiments, the photopolymer is removed by a chemical solutionafter the hole is created. In some embodiments, the protective layer isapplied to both sides of a glass wafer for purposes of etching holes inthe glass

In some embodiments, the hole is created by a laser. In someembodiments, the laser is applied to the surface of the glass substrate.In some embodiments, a wavelength of the laser is between 45 nm and 24μm. In some embodiments, a pulse duration of the laser is between 1femto second to 120 nanosecond. In some embodiments, the laser-createdhole is chemically etched prior to filling. In some embodiments, acoating is applied to a glass surface prior to laser processing. In someembodiments, the coating comprises a polymer, film or paste whichabsorbs the wavelength of the laser, thereby reducing the level of heatrequired to create the hole in the glass. In some embodiments, thecoating is subsequently removed after hole creation, either chemicallyor mechanically. The shape of the hole usually depends on the method andparameters used to create the hole.

Filling Through-Holes

The present invention features a method of filling a through hole in aglass substrate comprising coating a sidewall of the hole with at leastone layer of coating material and metallizing the hole with the pastematerial. In some embodiments, the method comprises coating a sidewallof the hole with at least one layer of a paste material and thermallyprocessing the coated hole prior to metallization. In some embodiments,the method comprises metallization of the through hole, followed bythermal processing. In some embodiments, the method further comprisesstrengthening the glass substrate prior to coating the sides of theholes for purposes of increased durability. In some embodiments, themethod further comprises cleaning the glass substrate prior to filling.

In some embodiments, the glass substrate is heat treated by curing at atemperature between 40° C. and 815° C. for borosilicate glass andorganic laminate materials and 40° C. to 1100° C. for synthetic quartzand ceramic based materials. In some embodiments, heat treating theglass substrate achieves hermeticity and interconnection between innerand surface metallization layers.

In some embodiments, the coating on the sides of the hole is parallel tothe direction of the through hole. In some embodiments, the hole iscoated on the sides of the hole with an organometallic compound, such assilicon based compounds. In some embodiments, the hole is coated on thesides of the hole with a glass rich paste. In some embodiments, thecoating on the sides of the hole is done by glass wetting. In someembodiments, the coating on the sides of the hole is done by reactiveinteraction with a surface of the hole. In some embodiments, the coatingof the sides of the hole is thermal processed at a temperature between40° C. and 815° C. for borosilicate glass materials.

In some embodiments, a first layer of coating the side of the hole isfor adhesion promotion. In some embodiments, the subsequent layers arefor conductivity and performance. In some embodiments, the performanceis defined as the input and output of an electronic signal between thetop surface and bottom surface of the glass substrate. In someembodiments, the performance is defined as the input and output ofelectrical power between the top surface and bottom surface of the glasssubstrate.

In some embodiments, the paste material comprises a metal, a glass fritcomposition, a solvent, a resin, a conductive or nonconductive inertadditive, or mixtures thereof. In some embodiments, the paste materialis a thick film paste containing a glass frit and a conductor. In someembodiments, the conductor is copper, silver, nickel or gold. In someembodiments, the hole is completely plated. In some embodiments, thehole is partially plated. In some embodiments, a conductive polymer isused to completely fill the hole. In some embodiments, the conductivepolymer comprises a filler metal. In some embodiments, the filler metalis a pure metal compatible with the conductor. In some embodiments, thefiller metal is a coated metal compatible with the conductor in someembodiments a silicon compound or adhesion promoter is in the paste. Insome embodiments, the conductive polymer is cured in the 40° C. to 515°C. range to cause sintering and adhesion of the conductive polymerfiller metal to the conductor in the hole itself or the wall of thehole. In some embodiments, a particle size of the metal ranges from 0.01and 24 microns for D50 (fifty percentile particle size distribution).

In some embodiments, the hole is metallized by plating. In someembodiments, the hole is completely metallized by applying pastematerial comprising a thick film paste composition. In some embodiments,the hole is partially metallized by applying the paste materialcomprising a thick film paste composition. In some embodiments, the holeis further metallized by plating. In some embodiments, metallizationcompletely fills the hole. In some embodiments, metallization partiallyfills the hole. In some embodiments, any remaining space in the hole isfilled with a conductive polymer. In some embodiments, the conductivepolymer comprises pure metal, coated particles or a mixture of pure andcoated particles. In some embodiments, the polymer comprises aconductive metal curing material that is Cu and/or Ag and/or Au filled.

In some embodiments, the metal curing material that is thermally curedin the 40° C. to 515° C. using conductive particles with size in the0.01 to 24 micron range for D50 (fifty percentile particle sizedistribution). In some embodiments, the conductive polymer is curedusing UV or equivalent wavelength exposure, or a combination of UVexposure and thermal, or thermal curing completely. In some embodiments,an outer surface of a conductive particle is Cu and/or Ag, and/or Au. Insome embodiments, the core of the conductive particles is differentcompared to the outer surface.

Paste Material

The present invention features a paste material for filling athrough-hole for improved adhesion and hermeticity in glass substrates.In some embodiments, the paste material comprises a metal, a glass fritcomposition, a solvent, a resin, a conductive or non-conductive inertadditive, or mixtures thereof. In some embodiments, the paste materialcomprises mixtures of metals, mixtures of glass frit compositions,mixtures of solvents, mixtures of resins, and mixtures of conductive ornon-conductive inert additives.

As defined by the Department of Defense's test method standards forseals, hermeticity is the effectiveness of the seal of microelectronicand semi-conductor devices with designed internal cavities. The failurecriteria for hermeticity vary depending on the application and aredefined by the Department of Defense's test method standards for seals.

As defined herein, the term “improved adhesion” is metallizationlift-off over about 1 Newton. Poor adhesion is metallization lift-off ator below about 1 Newton. Standard adhesion peel methods (Dupont H-02134)or wire soldering into fired pads may be included.

In some embodiments, the metal comprises a pure metal. In someembodiments, the metal comprises a metal compound. In some embodiments,the metal is combined with oxides and compounds of the metal andmixtures thereof. In some embodiments, the metal comprises copper,silver, gold, nickel, tungsten, molybdenum, silicon, aluminum, zinc,barium, boron, bismuth, titanium, metal compounds, or and a combinationthereof. In some embodiments, the particle size of the metal powderranges from 0.01 to 24 microns for D50 (fifty percentile particle sizedistribution). In some embodiments, a combination of powders withdifferent particle sizes and shapes can be mixed for through holefilling applications.

In some embodiments, the metal comprises of a coated particle. In someembodiments, the metal comprises a conductive powder, wherein theconductive powder comprises a core, and wherein the core is coated withcopper, silver, gold, nickel, tungsten, molybdenum, silicon, aluminum,zinc, barium, boron, bismuth, titanium, or a combination thereof.

In some embodiments, the glass frit composition comprises a mixture ofglass frits. In some embodiments, the glass frit composition comprisesthe oxide and compounds of the following materials: Ag, Al, B, Bi, Ce,Cu, Co, F, Pb, Al, Zn, Zr, Si, Ba, Ru, Sn, Te, Ti, V, Na, K, Li, Ca, andP. The particle size of the glass frit to be in the 0.01 to 24 micronrange for D50 (fifty percentile particle size distribution).

In some embodiments, the solvent comprises Terpineol, Texanol, Dowanol,butyl carbitol, butyl carbitol acetate, methyl-ethyl-butyl ethers,similar solvents used in thick film technology for curing or firingapplications, or a combination thereof.

In some embodiments, the resin comprises ethyl cellulose basedcompositions and mixtures. In some embodiments, the resin comprisesresin systems similar to ethyl cellulose based compositions andmixtures. In some embodiments, the resin is natural, synthetic or acombination thereof. The resin is normally dissolved using anappropriate solvent to produce a vehicle, with a viscosity like honey.The vehicle system is used to disperse the various ingredients in athick film paste for printing, patterning and through hole fillingapplications.

In some embodiments, the inert additive comprises tungsten, molybdenum,aluminum, zinc, zirconium, silicon, lanthanum, ruthenium, cobalt,nickel, their compounds and oxides, or a combination thereof.

In some embodiments, the paste material is mixed and dispersed using athree roll mill and/or other approaches, typical in thick filmtechnology, or a combination thereof. In some embodiments, the pastematerial fills the hole by printing, extrusion, dispensing, coating,injection or a combination thereof. In some embodiments, the filled holeis cured and/or fired in an air, nitrogen, doped nitrogen, CO/CO2,vacuum, other inert environments or a combination of thereof.

Processing Glass Substrates

The present invention features a method of processing a glass substratefor use in semi-conductor packaging applications. In some embodiments,the method comprises filling through-holes of the glass substrate with ametallized paste material using thick film technology, planarizing theglass substrate after metallization to clean and flatten a surface ofthe glass substrate, coating the surface of the glass substrate with atleast one redistribution layer of a metal, a metal oxide, an alloy, apolymer, or a combination thereof.

In some embodiments, the redistribution layer is a metal filledconductive polymer that is cured in the 40° C. and 515° C. temperaturerange. In some embodiments, the redistribution layer is plated forimproved performance and functionality. In some embodiments, the platingmaterial comprises one or a combination of materials, including Ni, Cu,Ag, Au, Pd, Pb, and Sn as major components.

In some embodiments, the redistribution layer is spin-coated onto theglass surface. In some embodiments, the redistribution layer is sprayed,screened or laminated onto the glass surface. In some embodiments, theredistribution layer is deposited using thick film technology. In someembodiments, the redistribution layer is deposited using thin filmtechnology.

In some embodiments, thick film technology uses pastes containing glassfrits that are deposited in patterned layers defined by screen printingand fused at high temperature onto a glass substrate. The paste isapplied onto a substrate, or through hole filled, and the paste issubsequently cured and/or fired, the firing temperature being in therange of 40° C. and 815° C. The paste ingredients (for a conductor) areparticles of metal, glass frit, additives, oxides, etc, dispersed in avehicle system. Thick film technology is apparent to those ordinarilyskilled in the art.

In some embodiments, in thin film technology, a metal is evaporated ordeposited on a substrate, and then a photoresist is applied, and thenexposed and developed to expose areas to be etched. The remainingdeposited metallization (after etching the unwanted areas) constitutesthe desired circuitry. The thin film deposited layer might containseveral different metallizations layers for adhesion, barrier andpassivation. In some embodiments, in thin film technology, an adhesionlayer is deposited onto the glass substrate. In some embodiments, theadhesion layer is usually tungsten, titanium, chromium or a combinationthereof. In some embodiments, the adhesion layer is followed by a metallayer. In some embodiments, the metal layer is copper, gold, or silver.In some embodiments, a diffusion barrier is deposited on the metallayer. In some embodiments, the diffusion barrier is nickel, tungsten,titanium, or chromium. In some embodiments, the diffusion barrier isfollowed by a passivation layer to protect the other layers fromoxidation. In some embodiments, the passivation layer is nickel or gold.Thin film technology is apparent to those ordinarily skilled in the art.

In some embodiments, the method further comprises firing the glasssubstrate. In some embodiments, the glass substrate is fired at atemperature between 385° C. and 959° C. In some embodiments, the methodfurther comprises curing the glass substrate. In some embodiments, theglass substrate is cured at a temperature between 40° C. and 515° C.

In some embodiments, the coated surface is cured in neutral or reducingatmospheres. In some embodiments, the coated surface is cured in air,nitrogen, or in a vacuum. In some embodiments, the coated surface iscured in doped atmospheres for higher performance.

Final Product

As seen in FIGS. 1 and 2, the present invention features a glasssubstrate (100) for use in semi-conductor packaging applications, saidglass substrate (100) comprising a top surface (111) and a bottomsurface (112), a through-hole (120) extending from the top surface (111)to the bottom surface (112) of the glass substrate (100), wherein thehole (120) comprises a first end (121), a second end (122), and asidewall (125).

In some embodiments, at least one interior layer (130) disposed insidethe hole (120). In some embodiments, at least one external layer (140)disposed on the top surface (111). In some embodiments, at least oneexternal layer (140) disposed on the bottom surface (112). In someembodiments, the interior layer (130) comprises at least one metallizedlayer. In some embodiments, the metallized layer comprises at least onemetallized paste composition. In some embodiments, the hole (120) issubstantially filled with at least one metallized paste composition. Insome embodiments, at least one metallized layer substantially occupiesthe volume of the hole. (120) after firing and curing the glasssubstrate (100).

In one preferred embodiment, the glass substrate comprises a pluralityof though-holes, wherein each through-hole comprises a first end, asecond end, and a sidewall. At least one interior layer is disposedinside each through-hole. The plurality of through-holes is eachsubstantially filled with at least one metallized paste composition. Atleast one metallized layer substantially occupies the volume of eachhole after firing and curing the glass substrate.

In some embodiments, a plurality of interior layers (130 a, 130 b, 130c) is disposed inside the hole. In some embodiments, a plurality ofexternal layers (140) is disposed on the top surface (111). In someembodiments, a plurality of external layers (140) is disposed on thebottom surface (112). In some embodiments, each interior layer (130)comprises at least one metallized layer. In some embodiments, eachinterior layer (130) comprises a plurality of metallized layers. In someembodiments, each metallized layer comprises at least one metallizedpaste composition. In some embodiments, each metallized layer comprisesa plurality of metallized paste compositions. In some embodiments, eachhole (120) is substantially filled with at least one metallized pastecomposition. In some embodiments, each hole (120) is substantiallyfilled with a plurality of metallized paste compositions. In someembodiments, at least one metallized layer substantially occupies thevolume of each hole (120) after firing and curing the glass substrate(100). In some embodiments, a plurality of metallized layerssubstantially occupies the volume of each hole (120) after firing andcuring the glass substrate (100).

In some embodiments, the top surface (111), bottom surface (112), andthe interior layer (130) are at a same level. In some embodiments, theinterior layer (130) is polished to remove any protruding metallization.In some embodiments, the top surface (111) and bottom surface (112) arepolished off to be at the same level as the interior layer (130).

In some embodiments, the hole (120) is at least partially filled usingthick film technology. In some embodiments, the hole (120) is at leastpartially filled by plating. In some embodiments, the hole (120) isplated at the first end (121), the second end (122), or a combinationthereof.

In some embodiments, an inner metallized layer differs in compositionfrom an outer metallized layer. In some embodiments, the hole (120)plating is metal. In some embodiments, the metal is copper, silver,gold, nickel, palladium or a combination thereof. In some embodiments,the hole (120) is a polymer conductive thick film. In some embodiments,the polymer conductive thick film is cured in a temperature between 40°C. and 515° C.

In some embodiments, the interior layer (130) comprises a copper thickfilm entirely, a silver thick film, and a copper thick film partially.In some embodiments, the interior layer (130) comprises a copper thickfilm and plated copper. In some embodiments, the interior layer (130)comprises plated copper, thick film copper, and plated copper. In someembodiments, the interior layer (130) comprises plated copper, thickfilm silver, and plated copper. In some embodiments, the interior layercomprises a copper layer, a silver layer, an electronic component,another silver layer, and another copper layer.

In some embodiments, the electronic component is disposed in theinterior layer (130). In some embodiments, the electronic component is acapacitor. In some embodiments, the electronic component is a resistor.In some embodiments, an electronic component material comprisescompounds or oxides of Ba, Bi, Ti, Sr, Ru, C, Ni, Fe, Pb, Al, Ca, Cu,Cr, Ag, Zn, Zr, V, or mixtures thereof. In some embodiments, when aconductor is a conductive polymer, the electronic component material isan organic polymer. In some embodiments, the organic polymer comprisescompounds or oxides of Ba, Bi, Ti, Sr, Si, Ru, Ti, C, Ni, Fe, Pb, Al,Ca, Cu, Cr, Ag, Zn, Zr, V, or mixtures thereof.

In some embodiments, the sidewall (125) is coated. In some embodiments,the coating is copper, silver, gold, glass, silicon compounds, or acombination thereof.

In some embodiments, the filled hole (120) is hermetic. In someembodiments, the filled hole (120) has a high conductivity. In someembodiments, the filled hole (120) has a low resistivity. In someembodiments, the resistivity is less than 25 milli-ohm/square. In someembodiments, the resistivity is less than 20 milli-ohm/square. In someembodiments, the resistivity is less than 15 milli-ohm/square. In someembodiments, the resistivity is less than 10 milli-ohm/square. In someembodiments, the resistivity is less than 5 milli-ohm/square. In someembodiments, the resistivity is less than 3 milli-ohm/square. In someembodiments, the resistivity is less than 2 milli-ohm/square. In someembodiments, the resistivity is less than 1 milli-ohm/square.

In some embodiments, the glass substrate of the present invention can beused for eliminating flex cables for displays. In some embodiments, theglass substrate of the present invention can be used for transparentscreen displays, CMOS sensors, optical signals, etc. In someembodiments, the glass substrate of the present invention can be usedfor in biomedical applications such as lab on a chip or DNA sequencingslides or other glass slides used for applying bio materials fortesting.

In some embodiments, the hole is polished prior to or after filling thehole. In some embodiments, the hole is polished from one or both sidesof the glass surface to produce a more uniform hole. In someembodiments, the hole may be cylindrical, conical, or varying indiameter throughout the hole.

In some embodiments, a separate metallization structure is attachedand/or stacked to the metallized glass substrate from one or both sides.In some embodiments, the separate metallization structure could beanother glass based structure, a high temperature co-fired (HTCC) or lowtemperature co-fired (LTCC) ceramic, a silicon or other semi-conductorstructures, a flex circuit or a printed wiring board. In someembodiments, the thickness of the attached and/or stacked structurecould have openings to accommodate devices attached to other glasssubstrates or stack layers.

As used herein, the term “about” refers to plus or minus 10% of thereferenced number.

EXAMPLES Example 1

As a non-limiting example, a CO₂ laser is used to drill through holes ina glass substrate.

Example 2

The following is a non-limiting example of filling a through-hole in aglass substrate. A thick film paste is used to fill the through hole.The paste is dried at or below 150° C. in air, nitrogen, doped nitrogen,CO/CO₂ or vacuum. The filled through hole is then fired up to 815° C.,or below the softening point of the glass substrate. This process can berepeated several times depending on through hole dimensions. In someembodiments, firing above the softening point of the glass substrate(above 815° C. for borosilicate type glass) without a support can causethe glass substrate to warp, and/or the glass substrate can conform to adesired shape, which may be useful in specialized applications.

Example 3

The following is a non-limiting example. A method of processing a glasssubstrate for use in semi-conductor applications: The glass substratewith conductive through holes is metallized on both surfaces. Multiplelayers, such as redistribution layers can be used based on theapplication. In one embodiment, integrated circuits and components areattached on one side, and a motherboard (PWB or other) is attached onthe other side.

Example 4

Non-limiting example of a Paste Material—Organic vehicles based on ethylcellulose or other resin systems; solvents including terpineol, dowanol,texanol and other solvent systems typically used in the thick filmindustry; glass frit compositions; copper powders and their oxides.

Example 4

Non-limiting example of a Final Product—Either thick film metallization(by itself or +plating), or thin film metallization with adhesion layer,barrier, conductor, barrier and ENIG or ENIPIG.

The disclosures of the following U.S. patents are incorporated in theirentirety by reference herein: U.S. Pat. No. 8,584,354, U.S.2013/0105211, WO2013138452, WO2012061304, U.S. Pat. No. 8,411,459, andU.S. 2013/0119555.

Various modifications of the invention, in addition to those describedherein, will be apparent to those skilled in the art from the foregoingdescription. Such modifications are also intended to fall within thescope of the appended claims. Each reference cited in the presentapplication is incorporated herein by reference in its entirety.

Although there has been shown and described the preferred embodiment ofthe present invention, it will be readily apparent to those skilled inthe art that modifications may be made thereto which do not exceed thescope of the appended claims. Therefore, the scope of the invention isonly to be limited by the following claims. Reference numbers recited inthe claims are exemplary and for ease of review by the patent officeonly, and are not limiting in any way. In some embodiments, the figurespresented in this patent application are drawn to scale, including theangles, ratios of dimensions, etc. In some embodiments, the figures arerepresentative only and the claims are not limited by the dimensions ofthe figures. In some embodiments, descriptions of the inventionsdescribed herein using the phrase “comprising” includes embodiments thatcould be described as “consisting of”, and as such the writtendescription requirement for claiming one or more embodiments of thepresent invention using the phrase “consisting of” is met.

The reference numbers recited in the below claims are solely for ease ofexamination of this patent application, and are exemplary, and are notintended in any way to limit the scope of the claims to the particularfeatures having the corresponding reference numbers in the drawings.

What is claimed:
 1. A method of filling a through hole in a glass substrate, said method comprising: a. coating a sidewall of the hole with at least one layer of coating material, wherein the coating is parallel to the direction of the through hole, wherein the coating material comprises an organometallic compound or a glass rich paste; and b. metallizing the hole with a paste material, wherein the paste material comprises a metal, a glass frit composition, a solvent, a resin, and a non-conductive inert additive.
 2. A method of filling a through hole in a glass substrate, said method comprising: a. coating a sidewall of the hole with at least one layer of coating material, wherein the coating is parallel to the direction of the through hole, wherein the coating material comprises an organometallic compound or a glass rich paste; and b. metallizing the hole with a paste material, wherein the paste material is a thick film paste containing a glass frit and a conductor.
 3. A method of filling a through hole in a glass substrate, said method comprising: a. coating a sidewall of the hole with at least one layer of coating material, wherein the coating is parallel to the direction of the through hole, wherein the coating material comprises an organometallic compound or a glass rich paste; b. metallizing the hole with a paste material; and c. filling the hole with a conductive polymer. 